Black Swallowtail: emerging this year or next?

by Louise
(St. Louis, MO)

I am confused about when to expect the BS cat in my garden to emerge from his chrysalis. He appears to be in the 3rd instar. Your site says ALL swallowtails overwinter. Even when they are this close to pupating this early (June 25) in the season?


Karen says:
No, I will have to change my wording on my first statement below to clarify that it is only the last brood of the summer that overwinters. Sorry for the confusion. Here is what I said (note the third statement)....

Black Swallowtails overwinter in the chrysalis stage.

They are first seen in April and May after emerging from their chrysalis.

There are 2 or 3 broods (generations) each summer....the second one emerging around mid-June and another in August or September.